1. Field of the Invention
The present invention relates to a sound-absorbing material using non-woven fabrics and a wiring harness with sound-absorbing material in which a sound-absorbing material and a wiring harness are integrated.
2. Description of the Related Art
In recent years, there has been a rapid growth in performance and function, centering on automotive vehicles, electronic products and the like. To accurately activate various pieces of electronic equipment such as automotive vehicles, electronic products and the like, a plurality of wires are used for internal wiring in the automotive vehicles, the electronic products and the like. Generally, the plurality of these wires are used in the form of a wiring harness. To obtain the wiring harness, a plurality of wires are assembled into a form necessary for wiring in advance. After necessary branching, connector mounting on ends and the like are applied, a wiring harness protection material which comes in various shapes such as a tape shape, a tube shape and a sheet shape is wound around the outer periphery of a wire bundle, thereby forming the wiring harness.
Further, sound-absorbing materials are provided in the interiors of automotive vehicles, houses and the like to enhance indoor silence. Conventionally, glass wool, rock wool, porous ceramics, waste cotton and the like have been used as sound-absorbing materials. However, due to problems such as workability, safety on human body, recyclability and environmental load, non-woven fabrics have been used as the above sound-absorbing materials in recent years (see, for example, Japanese Unexamined Patent Publication No. 2003-49351).
A sound-absorbing material described in patent literature 1 is such that a meltblown ultrafine staple fiber non-woven fabric is laminated on one side of a polyester-based fiber non-woven fabric. In the case of using such a laminated non-woven fabric as a sound-absorbing material, it is thought to be possible to enhance sound absorption performance in a specific frequency range, e.g. a frequency range of 1000 to 4000 Hz.
However, if it is tried to improve the sound absorption performance of the sound-absorbing material in a range other than the specific frequency range, e.g. a range below 1000 Hz, a basis weight of each non-woven fabric needs to be increased. However, if the basis weights of the non-woven fabrics are increased, it causes a problem of increasing a weight.
The present invention seeks to solve the above problem of the conventional technology and aims to provide a sound-absorbing material and a wiring harness with sound-absorbing material capable of absorbing sound in a wide frequency range from a low frequency to a high frequency and avoiding a weight increase.